Ultraviolet (UV) light is used to purify fluids due to its bactericidal effects and ability to inactivate viruses and enzymes. In particular, as UV light is absorbed, it causes disruption in the transcription and replication of DNA which ultimately kills the exposed microorganism. The UV region of the electromagnetic spectrum ranges from 100 to 400 nm. UV light in the range of 100-280 nm is the germicidal range that serves to inactivate enzymes, bacteria and viruses. The maximum germicidal effect is estimated to be in the range of 250-270 nm. Aside from the wavelength of light, the exposure requirement (energy received by a surface per unit area), is also a consideration that needs to be taken into account. After a certain point, the germicidal effect of any given exposure will realize diminishing returns, but an insufficient level of exposure can result in a situation in which malevolent microorganisms are merely wounded, allowing them to recover and replicate in a fluid that was thought to have been purified.
There are two popular species of ultraviolet reactor configurations. The first popular UV reactor configuration in the related art involves a cylindrical flow tube, through which the liquid flows, which is surrounded by a source of UV light that bombards the liquid from 360° along the length of the cylinder. The cylindrical flow tube is made of ultraviolet-transparent (“UV transparent”) material and serves to isolate the liquid from the source of UV light while allowing the UV light to pass through to the liquid. The source of UV light in these situations is often a set of tubular UV lamps distributed around the circumference of the cylindrical flow tube. The second popular UV reactor configuration is the opposite of the first. In the second configuration, the light is on the “inside” in an isolated cylinder that shares the same main axis as the flow tube. As a result, the fluid flows around the UV light source and is bombarded along the length of the flow tube from within.